A semiconductor memory device is known in which a memory cell array is divided into a plurality of blocks, sense amplifiers used for reading data are provided independently for each divided block of the memory cell array, and data can be written in memory cells of only all the divided blocks or of some of selected blocks. With such a semiconductor memory device, during a data write, sense amplifiers of the block not pertaining to the data write are made active, the same as during data read. Therefore, steady current will flow through sense amplifiers not pertaining to the essential operation.
As described above, with a conventional semiconductor memory device, during data write, sense amplifiers not pertaining to data write are made active, the same as during data read, allowing current to flow steadily. Power consumption will, therefore, increase. As the number of blocks increases, power consumption will increase correspondingly.